Today a gateway node such as e.g. the Gateway GPRS Support Node (GGSN) or the Packet data network GateWay (PGW) is one of the endpoints for the GPRS Tunneling Protocol-User plane (GTP-U) tunnel in a 3rd Generation Partnership Project (3GPP) communications system. The other endpoint for the GTP-U tunnel is a Radio Access Network, RAN, node such as e.g. an evolved Node B (eNB), a Node B (NB), a base station or a Radio Network Controller (RNC). All traffic originating or terminating in a wireless device has to go through the gateway. The term GPRS mentioned above is short for general packet radio service.
FIG. 1a illustrates the GTP-U tunnel and the GTP-Control plane (GTP-C) tunnel in a Wideband Code Division Multiple Access (WCDMA) system 100. WCDMA is also referred to as a Third Generation (3G) technology. The WCDMA system 100 comprises an NB/RNC 101, a Serving GPRS Support Node (SGSN) 103, a GGSN 105, a wireless device 115 and Internet 120. The WCDMA system 100 in FIG. 1a is exemplified with two wireless devices 115, however any other suitable number of wireless devices is equally applicable. Internet 120 may be represented by e.g. an Internet server.
In the example WCDMA system 100 in FIG. 1a, the GTP-U tunnel is between the NB/RNC 101 and the SGSN 103 and between the SGSN 103 and the GGSN 105. The GTP-C tunnel is also between the NB/RNC 101 and the SGSN 103 and between the SGSN 103 and the GGSN 105.
A 3G GTP-U direct tunnel is realized for WCDMA systems where the direct tunnel is between the RNC and the GGSN. This is illustrated in FIG. 1b. As seen in FIG. 1b, the GTP-C tunnel is between the NB/RNC 101 and the SGSN 103 and between the SGSN 103 and the GGSN 105 as in FIG. 1a. The difference between FIGS. 1a and 1b is the GTP-U tunnel. In FIG. 1b, there is a 3G GTP-U direct tunnel which is located between the NB/RNC 101 and the GGSN 105. The 3G GTP-U direct tunnel bypasses and relieves the SGSN 103 of transit traffic to and from the GGSN 105.
FIG. 2 illustrates the GTP-U tunnel and the GTP-C tunnel in a Long Term Evolution (LTE) system, 200. The LTE system 200 then comprises an eNB 201, a Serving GateWay (SGW) 203, a Packet data network GateWay (PGW) 205, a Mobility Management Entity (MME) 208, a wireless device 215 and Internet 220. The LTE system 200 in FIG. 2 is exemplified with two wireless devices 215, however any other suitable number of wireless devices is equally applicable. Internet 220 may be represented by e.g. an Internet server. As seen in FIG. 2, the GTP-C tunnel is between the eNB 201 and the MME 208, and between the MME 208 and the SGW 2023. The GTP-U tunnel in the LTE system 200 is between the eNB 201 and the SGW 203, and between the SGW 203 and the PGW 205.
The wireless devices 115, 215 illustrated in FIGS. 1a, 1b and 2 may each be a device by which a subscriber may access services offered by an operator's network and services outside operator's network to which the operator's network provide access, e.g. access to the Internet. The wireless devices 115, 215 may be any device, mobile or stationary, enabled to communicate over a radio channel in the communications network, for instance but not limited to e.g. user equipment, mobile phone, smart phone, sensors, meters, vehicles, household appliances, medical appliances, media players, cameras, Machine to Machine (M2M) device, Internet of Things (IoT) device or any type of consumer electronic, for instance but not limited to television, radio, lighting arrangements, tablet computer, laptop or Personal Computer (PC). The wireless devices 115, 215 may be portable, pocket storable, hand held, computer comprised, or vehicle mounted devices, enabled to communicate voice and/or data, via the access network, with another entity, such as another device or a server.
One problematic issue is that the packet core network introduces unnecessary latency and traffic load for end to end communication for wireless devices within the same coverage area. If an RAN node is separated/disconnected from the packet core network for any reason, wireless devices registered to that RAN node will lose the ability to send data on their existing packet data connections.